Cement-kiln feeder



Ma 10 1927.v f y A R. w. RYDER CEMENT KILN FEEDER Filed Nov. 14. 1925 Patented May 1o, i927.

ROBERT w.y RYDER, OF SAN FRANCISCO,

A1,62a191,y

PATENT OFFICE.

CALIFORNIA, ASSIGNOR T0 SANTA CRUZ PORTLAND CEMENT COMPANY, OF SAN FRANCISCO, CALIFORNIA, A-v CORPORATION OF CALIFORNIA.

CEMENT-KILN FEEDER.

Application lcd November 14, 1925. Serial No. 68,994.

This invention relates to Portland cement manufacture and has to do with means for feeding the raw mix into the revolving ce-4 ment kilns in the calcining of the material. i The principal objects of the invention are to provide a uniform delivery of the material to the kiln with a minimum ofentrained air, and reduce dust loss` to protect. the feeding apparatus against the intense heat 'of the kiln, provide for removal of foreign material from the mix being fed, and to. pro-` vide for minimum obstruction to draft in l cross section of the' feeder box as seen from.

the line 2--2 of Figure 1, and- Figure 3 shows a wedge used to lock the doors of the feeder box.

In the figures 1 represents the receiving lend of a tubular revolving cement kiln projecting into the wall at the lower portion of the stack 2, and 3 is a spiral conveyor arranged for feeding the raw mix from a bin hopper 4 to the kiln.

The conveyor 3 is mounted at its receiving end in a rectangular box 5 secured .to the lower end of the hopper and provided at the point of juncture with a sliding` gate 6 so that the fall of material into the box may be controlled or stopped.

This box is considerably larger than the conveyor so that any foreign matter such as bolts or other ieces of metal will fall or work through t e powdered material to a. point well below the screw of the conveyor and thus be kept from jammingl the conveyor or getting ntothe kiln. M

The ends of the box are formed preferably of castings as indicated, the one at the left 7 being provided with a stuing box 8 for the drive shaft 9 of the conveyor while thc right end 10 is provided with v a circular opening surrounded by a flange 11 adapted to receive the end of a steel tube 12 surrounding ,the kiln.

This tube is held in place within the cast head 10 of the box by means of a. pair of the conveyor and projecting` into rss'v eye bolts 13 pinned between lugs 14 on the head and engaging a split yoke or ring 15 clamped or otherwise secured to the tube, so

that upon drawing up the bolts the ring is y forced toward the head, and compresses suitable packing material 16 inserted between the two members to eiect a tight joint.

Surrounding this tube 12 is a heavy cast 1ron pipe 17 spaced about an inch from the tube by means of suitable spacers or lugs 18 so that an air' passage is formed between the tube and pipe extending entirely through the kiln dust chamber and into the kiln close to the lower edge of the open/end of the kiln as shown.

The screw of the conveyor it will be noted terminates some distance back of the extreme end of the tubeand pipe so that the material banks up against the end of the conveyor through its natural angle of .repose as indicated at 19 and vthus forms a protecting barrier against the intense heat of the kiln from destroying the conveyor.

The box 5 is providedwith a hinged lid 20 on top` and a hinged bottom 2l, the former being for inspection ofthe interior or removal of any light waste material such as stray sacks and the like` and the latter for [the removal of accumulated heavy foreign matter or the removal or insertion of the `conveyor itself and which is-purposely assembled of relatively short sections connected by gudgeons 22 projecting into the hollow shaft sections 23 of the conveyor,

The hinging off the bottom and top is shown in the enlarged cross section Figure 2 and wherein the doors 20 and 21 are steel plates braced by angle bars 24 each pivoted at 25 to a bracket 26 so that the late can open as a door, and lwhen closed 1t is held by metal wedges 27 (Figure 3) passing through openings cut in the standing le of the angles 24 and engaging U bolts 8 projecting from the longitudinally extending edge stiifening angleV bars 29. v

Thus whenthe 'doors are closed and the wedges lightly tapped into place the doors are drawn up tightly against flat surfaces to seal the o ning and any interstices are quickly fille and further` sealed with the powdered material upon admitting same from the hopper.

The lower door is preferably split along the line A so that a portion only of it may be opened if desired.

To drive the feeder, the drive shaft end 9 after passing the stuffing box is supported in a bearing 31 and connects to any-suitable source of power, such for instance as the variable speed motor dotted at 32 through an intermediate gear reduction as dotted at 33, flexible couplings as at 34 being interposed where necessary.

`In operation the material is fed into the revolving kiln and the feeder tube is completely protected from the hot gases by the cast iron pipe while at the same time the suction of the stack causes a constant stream of cold air to be drawn through the space between the tube and pipe thus effectually preventing a destructive rise of temperature of these members.

It should v-also be noted that the position of the feeder in entering the kiln in horizontal extension adjacent the lowergedge 0f the kiln preserves a maximum free space above for passage of the heat to the stack and the material being fed adjacent the lower wall of the kiln out of the direct current of the gases reduces to a great extent the loss of dust resulting with the earlier methods of chuting the material by gravity with entrained air into the kiln.

1. A cement kiln feeder comprising a tube in substantially horizontal extension, a spiral conveyor fitting therein for forcing material therethrough, said tube connecting with a material receiving box of larger internal dimensions, and said conveyor extending into t-he box whereby foreign heavy mat-ter delivered with the material to the box for feeding by the spiral conveyor may separate and fall below the working diameter of the conveyor, and a door on said box for the removal of such matter.

2. A cement kiln feeder comprising a tube iii-substantially horizontal extension, a spiral conveyor fitting therein for forcing material therethrough, said tube connecting with a material receiving box of larger internal dimensions, and said conveyor extending into the box whereby foreign heavy matter delivered with the material to the box for feeding. by the spiral conveyor may separate and fall below the Working diameter of the conveyor, a' door onsaid box, -and said conveyor being assembled in sectionsv removable through said door.

3. A cement kiln feedei` comprising a tube in substantially horizontal extension, a spiral conveyor fitting therein for forcing material therethrough. said tube connecting with a material receiving box of larger internal dimensions, and said conveyor extending into the box whereby foreign heavy matter delivered with the material 'to the box for feeding by the spiral conveyor may separate and fall below the working diameter of the conveyor, a door on the under side and a door on the upper side of said box.

4. In a feeder of the character described, a box for receiving the material to be fed, a tube projecting therefrom, and a spiral conveyor wit-hin the tube arranged to convey material from the box through the tube, said tube being provided with a flange ring and bolted to the end of the box, and packing material between said flange and the box.

5. lln a cement roasting kiln having a stack at oney end, a pipe extending through'the lower part of the stack into the kiln, a tube spacedly supported within the pipe to provide an air channel between the pipe and rtube from without the stack to within the ported therefrom to provide through air channel space therebetween to the kiln only, and a spiral conveyor mounted for rotation within said `tube terminating short of the inner end ofthe tube.

l ROBERT W. RYDER. 

